Quantum mechanical calculations on the electronic structure of small molecules have shown that ab initio molecular orbital theory is a very useful way to study intermolecular interactions. We propose studies in the areas of ion hydration H-bonding, protein electrostatic potentials, enzyme mechanisms and "high energy" compounds which will use these molecular orbital techniques. Some of these results might have wider biological applications in the areas of membrane transport, enzyme inhibitors and drug design. BIBLIOGRAPHIC REFERENCES: Electrostatic Properties of Proteins: Role of the Aqueous Solution in Determing Protein Sceondary and Tertiary Structure, by P. A. Killman, d.M. Hayes and I.D. Kuntz, and "Environmental Effects on Molecular Structure and Properties", E. Bergmann and B. Pullman, ed., Dordecht, Holland (1976). The Electrostatic Polential of Proteins. I. Carboxypeptidase A., by D.M. Hayes and P.A. Kollman, J. Amer. Chem. Soc. (in press, Feb., 1976).